The disclosure relates to forming shaped thermoplastic articles having smooth peripheries. Many thermoplastic articles have sharp edges formed upon molding or cutting the article from a feedstock sheet. Such sharp edges can damage thin plastic films or flesh which they contact, and smoothing the edges is desirable. Described herein are methods of forming a smooth periphery for such sharp-edged articles by rolling over the sharp edge. The smoothing operation is performed by forming a deflectable flange including a bend region separated from the potentially sharp peripheral edge by a spacer, deflecting a portion of the deflectable flange, and softening at least one bent portion of the deflectable flange to yield a smooth periphery upon cooling. The deflection can include curling the spacer at or near the peripheral edge.

The present invention relates to an external cooling system for a molten film tube produced by a blown film tubular extrusion process, comprised of one or more enclosures with one or more respective cavities that directly receive a portion of cooling gas emanating from one or more associated cooling elements. Each enclosure includes a port containing a variable exhaust device and optional flow buffer, acting to maintain a pressure differential between the cavity and an adjacent inside volume of the molten film tube, adjustable to optimize molten film tube stability cooling element efficiency and spaced apart dimension between cooling elements. Significant increases in production speeds are achieved with improved film quality over an increased range of tubular film sizes, down to a minimum size which occurs when operating at zero internal to molten film tube pressure.

The present invention relates to an external cooling system for a molten film tube produced by a blown film tubular extrusion process, comprised of a divergent cooling element with a divergent cooling interface containing a cooling gas deflector spaced adjacent to the molten film tube and providing an expelled cooling gas (i) in a path opposing the flow of the molten film tube toward a first exit gap and (ii) in a path with the flow of the molten film tube toward a second exit gap. A minimum gap between the divergent cooling interface and the molten film tube occurs at the first exit gap and/or the second exit gap. Advantageously, the divergent cooling interface is provided with one or more compound angles to maximize stability and cooling efficiency. Additionally, multiple cooling elements can preferably be arranged in a stackable configuration to achieve higher throughput rates. Operation is characterized by improved film holding forces without the presence of high noise levels or detrimental vibration, flutter, and drag. Additionally, employing simplified single air delivery channels, and a stackable design, significantly reduces complexity and manufacturing costs.

The present invention relates to an apparatus for producing inline stretched tubular foils by the blowing process, having a blown foil system comprising an extruder, a blowing head, a cooling ring, a calibrating basket, a flat laying unit and a reversing turret haul-off, having a stretching system for monoaxially stretching the laid flat foil in the machine direction and with a first thinness control system which operates segmented control zones in the cooling ring to form thinness sections so that, during stretching, a foil is produced with a thickness profile having the smallest possible deviations from the medium foil thickness over the complete foil width. To increase the accuracy and speed of the first thinness section control system, a second thinness section control system is provided which controls two opposing heat sources between the calibrating basket and the flat laying unit and which can be connected to the first thinness section control system.

The present invention relates to an external cooling system for a molten film tube produced by a blown film tubular extrusion process. Embodiments of the present disclosure provide a unidirectional cooling element having a unidirectional cooling interface containing a cooling gas deflector spaced adjacent to the molten film tube. The unidirectional cooling element operably expels cooling gas in a path with the flow of the molten film tube toward an exit gap formed between the unidirectional cooling interface and the molten film tube. The minimum gap between the unidirectional cooling interface and the molten film tube occurs at the exit gap, and advantageously, the unidirectional cooling interface is provided with one or more compound angles to maximize stability and cooling efficiency.

The invention relates to a device and a method for calibrating a blown film (6), said device comprising: a tubular region with at least one inner wall (55), through which region the blown film can be passed; a liquid reservoir (82), which can be used to provide a liquid and which is situated above the tubular region, the liquid being guidable between the inner wall (55) and the blown film; and a suctioning device (B), situated below the tubular region, for suctioning off at least part of the liquid from the blown film. At least one liquid-permeable element (92) is provided, said element surrounding at least parts of the periphery of the blown film (6). This device permits the distance of the liquid-permeable element from the main axis of the blown film to be altered.

The present invention relates to an external cooling system for a molten film tube produced by a blown film tubular extrusion process. Embodiments of the present disclosure provide a unidirectional cooling element having a unidirectional cooling interface containing a cooling gas deflector spaced adjacent to the molten film tube. The unidirectional cooling element operably expels cooling gas in a path with the flow of the molten film tube toward an exit gap formed between the unidirectional cooling interface and the molten film tube. The minimum gap between the unidirectional cooling interface and the molten film tube occurs at the exit gap, and advantageously, the unidirectional cooling interface is provided with one or more compound angles to maximize stability and cooling efficiency.

The present invention relates to an external cooling system for a molten film tube produced by a blown film tubular extrusion process, comprised of one or more enclosures with one or more respective cavities that directly receive a portion of cooling gas emanating from one or more associated cooling elements. Each enclosure includes a port containing a variable exhaust device and optional flow buffer, acting to maintain a pressure differential between the cavity and an adjacent inside volume of the molten film tube, adjustable to optimize molten film tube stability cooling element efficiency and spaced apart dimension between cooling elements. Significant increases in production speeds are achieved with improved film quality over an increased range of tubular film sizes, down to a minimum size which occurs when operating at zero internal to molten film tube pressure.

The invention relates to a method for the extrusion and labelling of a packaging tube (14), comprising the following successive steps performed on an extrusion-labelling line, namely: a) forming a partially or fully tubular label (17) from a film (12); b) introducing the label (17) into a calibration element (22); c) extruding a tubular body (13) on the side of the concave surface of the label (17); d) bringing the external surface of the tubular body (13) into contact with the concave surface of the label (17), step (c) being performed in the calibration element (22). The invention also relates to an extrusion-labelling device and a packaging tube.

The disclosure relates to forming shaped thermoplastic articles having smooth peripheries. Many thermoplastic articles have sharp edges formed upon molding or cutting the article from a feedstock sheet. Such sharp edges can damage thin plastic films or flesh which they contact, and smoothing the edges is desirable. Described herein are methods of forming a smooth periphery for such sharp-edged articles by rolling over the sharp edge. The smoothing operation is performed by forming a deflectable flange including a bend region separated from the potentially sharp peripheral edge by a spacer, deflecting a portion of the deflectable flange, and softening at least one bent portion of the deflectable flange to yield a smooth periphery upon cooling. A liner sheet may be attached to the feedstock sheet prior to, during, or after forming and can be peelable therefrom.